Rheumatoid Arthritis Support Group
Rheumatoid arthritis is a chronic, inflammatory, multisystem, autoimmune disorder. It is a disabling and painful condition which can lead to substantial loss of mobility due to pain and joint destruction. The disease is also systemic in that it often also affects many extra-articular tissues throughout the body including the skin, blood vessels, heart, lungs, and...

I heard early on with my RA, that movement of joints helps to distribute synovial fluid throughout the joint, theoretically helping all the articulating surface. However, that doesn't account for joint damage, such as messed up synovium, osteoarthritis, and whatever. And remember, joint pain is likely caused by inflammation of synovial membranes.
I've tried to keep moving, but I'd recommend you talk to your doctor.
I'd also suggest, if you have unresolved pain, asking for a referral for physical therapy if that's possible. PT's have helped me understand that some very basic things I was doing incorrectly - not related the the RA itself - were making the symptoms worse. Under their guidance, I changed a few routine things (like the position of the seat when i'm driving) and broke a few bad habits (the way I sit in the chair when i'm practicing my horn, which is a few hours a day) and was taught to walk correctly (I'd been sort of sliding my feet instead of lifting them). All of those things in combination have made a big difference in my overall achiness and soreness, even though they weren't necessarily related to the RA issues, and that's helped me overall.
Gentle hugs to you, dear.
Be very slow and careful with what you try. Also, there are physiotherapists in hospitals that specialize in RA exercises. You should see if you can find one. In Canada, they don't cost any money in the hospital. That might be another route to start at.